Wheeled shoe accessories

ABSTRACT

A wheeled shoe accessory specifically adapted for rolling in a direction other than a direction in which the user&#39;s shoes are oriented. The wheeled shoe accessory includes a rigid board having a length sufficient to span a width of a shoe placed sideways across the board, with the board supporting an arch region of the shoe. At least one axle assembly is secured to a lower surface of the board. The axle assembly includes an axle and at least one roller rotatably mounted on the axle. At least one releasable fastener is joined to the board and configured to secure the board to the shoe sole. The user experience is similar to that of a skateboard, but with decoupled feet for individual maneuverability of each wheeled shoe accessory.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part (and claims the benefit of priority under 35 USC 120) of U.S. application Ser. No. 10/847,242, filed May 17, 2004, which is a continuation of U.S. application Ser. No. 10/081,388, filed Feb. 20, 2002, now U.S. Pat. No. 6,764,082. The disclosure of the prior applications are considered part of (and is incorporated by reference in) the disclosure of this application.

TECHNICAL FIELD

This invention relates to wheeled shoe accessories and to shoes for use with such accessories.

BACKGROUND

There have been several proposals over the last century, and earlier, for walking shoes that can be readily converted to function temporarily as roller skates. A principal advantage to such shoes is the enhanced flexibility in transportation modes that they afford. Most are familiar with the rigid skate frames from several years ago that strapped to the underside of practically any normal walking shoe to permit the wearer to roll upon four wheels arranged two forward, two rear, in a forward or normal walking direction as in a standard roller skate. There is at least one walking shoe on the market that contains wheels that can be retracted into the sole of the shoe for walking, and then extended for rolling. Of course, such shoes require soles with thicknesses sufficient to fully contain such rollers when retracted, but have the advantage of not requiring their rolling parts to be carried separately while walking.

In a rolling mode with these and standard roller skates, the wearer generally is able to propel himself along with alternating forward thrusts with each foot, in a motion similar to ice skating. The direction of travel is generally determined by the fore-aft or toe-heel axis of the foot. In-line skates have their wheels aligned along the fore-aft center line of the shoe, and can provide some directional control by tilting the skate to change the camber of the wheels. Some in-line skates have been employed for sliding down railings in a direction perpendicular to the fore-aft shoe centerline, either by sliding down the railing with the railing positioned between a middle pair of rollers, or on skid plates between the wheels.

There is another shoe that has a removable roller mounted in a cavity the heel of the sole. For walking, the roller can be completely removed from its cavity. In a rolling mode, the wearer can, with practice and balance, roll in a forward direction upon the cylindrical roller with ankle locked and shin flexed. To obtain forward momentum, the wearer is instructed to run on the forward portions of the soles, and then lean back to engage only the heel rollers of both shoes with the ground for sustained rolling in the fore-aft direction as determined by the roller geometry and orientation.

Skateboarding is yet another mode of transportation and sport popular with young people. Skateboards are generally characterized as boards supported by forward and rear “trucks,” each having a pair of wheels mounted upon a tiltable axle. While rolling forward on the board, side-to-side weight fluctuations tilt the board and cause a shift in the rolling direction of the wheels to provide controllable steering of the board. The rolling direction is thus determined by the orientation of the wheel axles, although the normal rolling direction is along a major fore-aft axis of the board. It is common for the skateboarder to place her feet at an angle with respect to the major board axis, with one foot behind the other, similar to the stance of a surfer on a surfboard.

SUMMARY

According to one aspect of the invention, a wheeled shoe accessory includes a rigid board having upper and lower surfaces and defining a longitudinal axis configured to be oriented along a rolling direction of the wheeled shoe accessory, the upper surface of the board having a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear. In some embodiments, the board is sized to fit entirely under the piece of footwear. Preferably, the board is of a length, measured along the longitudinal axis, of between about 8 and 14 inches, and is of a width, perpendicular to its longitudinal axis, of between about 2½ and 4 inches.

At least one axle assembly is secured to the lower surface of the board. The axle assembly includes an axle and at least one roller rotatably mounted on the axle for rolling in the rolling direction. Preferably, the axle assembly includes a compliant mount resiliently deformable and secured to the lower surface of the board, the compliant mount defining a canted kingpin axis. The axle is secured to the compliant mount and rotatable about the canted kingpin axis for inducing yaw with respect to the rolling direction. In some configurations, the wheeled shoe accessory includes first and second axle assemblies with their compliant mounts secured to the lower surface of the board such that their canted kingpin axes are in opposing directions to one another.

The wheeled shoe accessory also has at least one releasable fastener configured to secure the board to an underside of the piece of footwear to retain the wheeled shoe accessory to the piece of footwear during use. In some embodiments, the releasable fastener is a projection extending upwardly from the upper surface of the board and configured to be received by a receptacle defined by a sole of the piece of footwear. In one example, the projection is of a shape selected to prevent rotation of the board about an axis normal to the board with the projection received in the piece of footwear. Preferably, the projection is elongated with its length extending along the longitudinal axis of the board. In a presently preferred embodiment, the releasable fastener is a substantially rectangular mounting boss having a height of about ¾ inch, a length of about 1⅛ inch, and a width of about ¾ inch. Preferably, the releasable fastener is configured to permit the piece of footwear to be selectively positionable on the board in either of two positions, each with the piece of footwear angled with respect to the rolling direction. For example, the releasable fastener may be securable to the board in either of at least two angular orientations. In one example, the releasable fastener defines a center axis and opposing undercuts on either side of the center axis for receiving an attachment mechanism embedded in an underside of the piece of footwear. Preferably, the undercuts defined by the releasable fastener are of an elongated shape spanning the width of the releasable fastener and have a height of about ⅛ inch and a depth of about 3/16 inch.

In some embodiments, the wheeled shoe accessory also includes an orientation plate secured to the upper surface of the board and configured to receive the releasable fastener. The orientation plate defines a protrusion along its upper surface to align the received releasable fastener in a particular orientation with respect to the board's longitudinal axis.

In another aspect, an article of footwear includes a sole, an upper portion joined to the sole, and an attachment mechanism embedded in the sole for securing a wheeled shoe accessory to the sole. The attachment mechanism includes a body defining an elongated receptacle and a longitudinal axis, the receptacle defining a center axis and configured to receive a mounting boss of a wheeled shoe accessory. In some embodiments, the receptacle defines a substantially rectangular opening. The attachment mechanism also includes at least one manually operable lock control device configured to engage and retain the received mounting boss within the receptacle. For example, in some embodiments, the lock control device includes a button actuator disposed in the body along the longitudinal axis of the body and accessible from the side of the sole. A retainer arm is disposed in the body and joined to the button actuator, the retainer arm configured to engage and retain the received mounting boss in the receptacle with the retainer am in an engagement position. A spring is disposed in the body and biases the retainer arm toward its engagement position. Preferably, the lock control device includes two oppositely directed buttons joined to respective retainer arms configured to engage the mounting boss from opposite directions.

Some other aspects of the invention feature a rigid board for a wheeled shoe accessory, the board having upper and lower surfaces and defines a longitudinal axis configured to extend along a rolling direction of the wheeled shoe accessory. The upper surface of the board has a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear.

According to one such aspect, the board defines mounting holes arranged to mount at least one axle assembly on the lower surface of the board, and includes a projection extending from its upper surface and configured to selectively secure a releasable fastener in either of two selectable orientations with respect to the longitudinal axis of the board. In some embodiments, the projection his two elongated ribs oriented at different angles with respect to the longitudinal axis of the board, and a central post defining a threaded hole therein for receiving a threaded fastener to secure the releasable fastener to the board. According to another such aspect, the board defines a generally square recess in the upper surface along the longitudinal axis for receiving an orientation plate for selectively positioning a releasable fastener secured to the upper surface of the board in a particular orientation with respect to the board's longitudinal axis. Preferably, the recess has a side length of about 1¼ inches and a depth of about 0.2 inch. In some embodiments, the board further defines a hole therethrough at a center of the recess of about ¼ inch in diameter.

Various implementations of the concepts disclosed herein enable an enhanced user experience resulting from rolling in a direction other than a walking direction, while allowing individual foot maneuverability. Unlike skateboarding and surfing, the user's feet are decoupled to permit individual foot angulations and travel paths, while allowing the user to face at an angle to the general direction of motion. As a result, wheeled shoe accessory users can perform complex foot movements while rolling sideways. In addition, the disclosed wheeled show accessories can be employed for other purposes when not secured to footwear, such as by serving as hand-held toys for play. For example, decorative covers may be placed over the releasable fasteners, such as to simulate miniature characters “riding” the boards. Alternatively, the releasable fastener may be replaced with a flat plate that enables the board to be ridden by smaller children, or by larger children on only one foot in standard footwear. Hand grips may also be releasably secured to the fasteners, enabling a user to roll on either one or two pairs of such wheeled shoe accessories, at least partially supported on his or her arm or arms.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 illustrate sidewalk “surfing” and grinding, respectively, with shoes having rollers in their soles.

FIGS. 3 and 4 are partial side and bottom views, respectively, of a wheeled shoe.

FIGS. 5-7 are side, bottom and back views, respectively, of a right shoe equipped with a steerable truck assembly.

FIG. 8 is a back view of a left shoe equipped with a steerable truck assembly.

FIG. 9 is a bottom view of a second shoe with a truck assembly.

FIG. 10 is a cross-sectional view, taken along line 10-10 in FIG. 9.

FIG. 11 is a side view of the truck assembly of the shoe of FIG. 9.

FIGS. 12 and 13 are bottom and back views, respectively, of a third shoe with a truck assembly.

FIG. 14 is a side view of the truck assembly of the shoe of FIG. 12.

FIGS. 15-16 are side and bottom views, respectively, of a shoe equipped with a double truck assembly.

FIG. 17 is a rear view of the shoe of FIG. 15, with the double truck assembly shown in cross-section.

FIGS. 18 and 19 are back views of a shoe with a retractable wheel assembly in the arch region of the sole, with the wheel assembly shown in its extended and retracted positions, respectively, and the sole shown in cross-section.

FIG. 20 is a side view of a two-wheeled truck assembly, with the wheels shown in dashed outline.

FIG. 21 is an exploded view of the truck assembly of FIG. 20, without the wheels.

FIGS. 22 and 23 are perspective views of the axle and mounting bracket, respectively, of the truck assembly of FIG. 20.

FIGS. 24 and 25 are back views of left and right shoes, respectively, equipped with both steerable truck assemblies and non-steerable wheels.

FIG. 26 is a bottom view of the shoe of FIG. 25.

FIG. 27 is a perspective view of a wheeled shoe accessory secured to a shoe, with the axis of the board of the accessory oriented at 45 degrees to the heel-toe axis of the shoe.

FIG. 28 is an exploded view of the components of FIG. 27.

FIG. 29 is a perspective view of the embodiment of FIG. 27, showing only the board and fastening means.

FIG. 30 is an exploded view of the components of FIG. 29, with the fastening components oriented to place the heel-toe shoe axis perpendicular to the rolling direction.

FIG. 31 is a perspective view of the board of the accessory.

FIG. 32 is a perspective view of the board with assembled releasable fastener.

FIG. 33 is an exploded view of the components of FIG. 32, with the fastener oriented to place the heel-toe shoe axis perpendicular to the rolling direction.

FIG. 34 is a perspective view of the orientation plate.

FIG. 35 is a perspective view of the releasable fastener.

FIG. 36 is a bottom perspective view of the portion of the fastener embedded in the footwear.

FIG. 37 is an exploded view of the components of FIG. 36.

FIG. 38 is a longitudinal cross-sectional view of the fastening components in an engaged position.

FIG. 39 is a perspective view of an axle assembly.

FIG. 40 is an exploded view of the board configured with a flat plate.

FIG. 41 is an assembled view of the components of FIG. 40.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate that many of the attitudes or stances assumed by surfers and skateboarders may also be obtained with shoes having rollers in their soles, with the rollers specifically adapted to roll along in a direction other than the walking direction, in accordance with several aspects of the present invention. For example, FIG. 1 shows a user 10 rolling along a concrete sidewalk 12 with his feet oriented generally perpendicular to his direction of motion. Shoes 14 have rolling elements 16 in the arch region of their soles, enabling the user to balance his or her weight directly on the rolling elements for lateral motion. Preferably, there is sufficient room in the toe region of the flexible shoe soles, beyond the rolling elements 16, to allow the user to run or walk on the toe regions without engaging the rollers. This can be useful for obtaining a running start before jumping into a surfing position on the rollers for continued motion. In some instances, the rollers may enable surfing along an edge 18 of a curbstone, as shown in FIG. 2, or an inclined railing or hand rail.

As an alternative to a grinding roller, a grinding plate 52 can be employed, embedded in the sole along the centerline of the shoe, as shown in FIGS. 3 and 4. Grind plate 52 has a concave central portion for receiving and sliding along a railing or such. In this particular embodiment, the shoe is also equipped with slide plates 54 overlaying the sides of the sole in the arch region of the shoe, for engaging a rail in combination with grind plate 52 for certain maneuvers.

Steering control may also be accomplished by mounting the rolling members to the sole with compliant mounts, such as by incorporating a desired amount of compliance in the axle-pin mounting structure within the shoe sole.

More aggressive maneuverability is provided with a roller or wheel mount that induces a change in the wheel axle orientation in response to a steering input. For example, the shoe 82 in FIGS. 5-7 is equipped with a full axle truck assembly 84, of a similar type to those commonly employed in pairs on skateboards. The base 86 of truck assembly 84 is securely attached to the sole of the shoe in its arch region. Truck assembly 84 carries an axle 88 about which two generally cylindrical rollers 90 rotate independently, of a construction similar to skateboard wheels. As shown in FIG. 7, axle 88 has a pin 92 that is received in a socket of base 86 and can freely rotate within the socket. Axle 88 is also secured to base 86 by canted shoulder bolt 94, between two compliant bushings 96 a and 96 b. This arrangement causes axle 88 to slightly rotate in a steering sense (i.e., in the plane of FIG. 6) when it is tilted in the plane of FIG. 5 by compression of bushings 96 a and 96 b, providing intuitive directional (i.e., yaw) control.

Looking in combination at FIGS. 7 and 8, both of a pair of shoes can each be equipped with a truck assembly 84, for independent turning control of each foot in a sideways rolling, “surfing” mode. In the illustrated arrangement, the left foot truck axle 88 has its pin 92 extending to the left, while the right foot truck axle 88 has its pin 92 extending to the right, such that the truck axles pivot in opposite sense when their respective shoes are tilted in the same sense, for turning the truck axles out of phase with one another.

Truck assemblies 84 can be mounted to the shoe sole for quick removal to transition to a walking or running mode. In FIGS. 9-11, truck assembly 84 a has four quick release fasteners 98 for releasably securing the base of the truck assembly to the shoe sole. In FIGS. 12-14, on the other hand, the entire truck assembly 84 b is secured to the shoe sole with a single quick release pin 100 that is readily grasped and pulled from the shoe sole by ring 102. When in place, pin 100 extends through a hole 104 in a mounting boss 106 extending from the base of truck assembly 84 b, enabling the truck assembly to be mounted in either of two opposite orientations as desired for particular rolling directions and steering modes. As shown, mounting boss 106 is in the form of a projection extending upward from the upper surface of board 84 b and is configured to be received in a receptacle defined in the sole of the shoe.

Referring to FIGS. 15-17, shoe 108 has a double truck assembly 110 mounted beneath in the arch region of the sole. As shown, the base 114 of the truck assembly 110 has a length sufficient to span the width of the shoe sole placed sideways across the truck assembly, with the truck assembly supporting an arch region of the shoe, while also being sized to fit entirely under the shoe. Truck assembly 110 supports two independently tiltable wheel axles 112, each with a corresponding pivot pin 92 rotatable within a corresponding socket of the joint truck assembly base 114. Truck axles 112 are arranged in opposition for more aggressive steering sensitivity, giving shoe 108 all of the steering capability of a traditional skateboard, all within the width W₂ of the shoe sole rather than requiring a long board on which both feet are placed. Preferably, the overall wheelbase WB of double truck assembly 110 is about 2.0 inches (51 millimeters) or less. In one preferred embodiment, the wheelbase WB is about 2.0 inches (51 millimeters), and the fore-aft distance T_(B) between wheel midplanes is about 3.0 inches (76 millimeters), in a men's size 9 shoe with an overall sole length L_(S) of about 12 inches (30.5 centimeters). Thus, the wheel center track width T_(B) and wheelbase WB were about 30 percent and 20 percent of the shoe length, respectively. With two such shoes 108, a wearer can relatively position his or her feet in any number of positions while rolling sideways and steering, enabling maneuvers impossible with skateboards. As with some of the other embodiments described above, the toe and ball region 113 of the sole of shoe 108 is unobstructed by the truck assembly and its wheels 90, enabling the wearer to toe-walk on the front portion of the sole when not rolling. Heel-walking is also possible on the exposed heel surface 111 of the sole. Preferably, the sole is flexible forward of the arch region, for more comfortable walking. As with the above truck embodiments, double truck assembly 110 can be releasably mounted to the shoe sole.

The shoe 116 of FIGS. 18 and 19 has a two-wheeled roller assembly 118 mounted in its arch region for rolling in a sideways direction (similar to the shoe of FIG. 15), but configured to be readily retractable into the sole of the shoe for walking. In its extended position (FIG. 18), wheels 90 are partially disposed below the lower surface 120 of the shoe sole, and held in that position by a manually operable latch 122. When retracted (FIG. 19), the entire roller assembly 118 is contained within the recess 124 defined in the shoe sole. Latch 122 and axle 126 are both mounted to the shoe to pivot about respective pins 128 and 130, and biased by torsion springs (not shown) toward the positions shown in FIG. 19. It will be understood that such retractability is readily incorporated into several of the above-described roller configurations.

FIGS. 20-23 illustrate a steerable roller truck assembly 132 for use in skates, skateboards, or the like. The illustrated example can be constructed with an advantageously low overall height “H_(T)” of less than about 1.0 inch (25 millimeters), for example, for incorporation into the sideways-rolling shoe embodiments shown above. The three primary components of the assembly are a rigid mounting bracket 134, two compliant wedge-shaped bushings 136, and an axle 138 that carries two wheels 90. To assemble the truck assembly, the two wedge-shaped bushings are first placed into corresponding compartments on either side of a central web 140 of bracket 134. Next, axle 138 is slid over a rigidly mounted pin 142 of bracket 134 until it contacts the angled front surfaces of the bushings. In place, axle 138 cooperates to retain bushings 136 in their compartments. Axle 138 is axially retained on pin 142 by a retaining clip 144 or other fastener means. An adjustable locknut (not shown) at the distal end of pin 142, for example, may be employed to maintain a bushing preload over time, if the axle is configured to leave a gap between the axle and bracket at inner end of the axle as shown. This arrangement also allows bushing compliance to slightly cushion normal wheel loads, as well, and a secondary bushing washer (not shown) may be placed between the axle and the bracket at the inner end of pin 142 if desired. Alternatively, axle 138 may be configured to slide along pin 142 until it contacts a rigid stop surface of bracket 134. During use, torque applied to axle 138 about bracket pin 142 resiliently compresses one or the other of the bushings to enable steering of the axle about pin 142. Bushings 136 can be molded of polyurethane, with a hardness of about 50 to 95 shore A, for example.

Referring to FIG. 22, axle 138 has a central body 146 that defines an open circular slot 148 for receiving the pin of the bracket. Slot 148 encompasses, in cross-section, more than 180 degrees of a defined circle, so as to radially retain the pin. The open side of slot 148 accommodates the central web of the bracket. Surfaces 150 adjacent slot 148 bear against the angled surfaces of the bushings in use. An axle pin 152 of about 0.25 inch (6 millimeters) in diameter is rigidly secured within a bore of body 146, and is configured as known in the art to carry the wheels.

FIG. 23 illustrates the structure of mounting bracket 134. Pin 142 is of about 0.25 inch (6 millimeters) in diameter, pressed into a hole in the lower portion of the bracket and soldered to central web 140 for added support. A rear wall 154 of the bracket extends from the central web around the rear corners of the bracket, to define the cushion compartments 156. A groove 158 at the distal end of pin 142 receives the retaining clip.

FIGS. 24-26 show a pair of shoes 160L and 160R, each with a steerable truck assembly 84 as well as a non-steerable wheel 162. In each shoe, the non-steerable wheels are shown inboard of the truck assemblies 84 and provide a third contact wheel for added stability of each shoe, as compared with the embodiment of FIGS. 7 and 8. Wheels 162 are each mounted about for rotation about their own axle 164, laterally spaced from the truck assemblies 84 and supported between rigid flanges 166 extending from a common base 168 of the truck assembly.

FIGS. 27 illustrates one embodiment of a wheeled shoe accessory 200 attached to the sole 210 of an article of footwear 220. Referring to FIGS. 28-30, wheeled shoe accessory 200 includes a board 300, at least one axle assembly 370 secured to the lower surface of board 300, an orientation plate 310 secured to board 300, and a releasable fastener 320 configured to secure board 300 to the sole of the article of footwear. Board 300, further illustrated in FIG. 31, is generally rigid and defines a center axis 302 and a longitudinal axis 304 along a rolling direction. In one aspect, board 300 has a length along the longitudinal axis 304 of 11 inches and a width of 2.75 inches. Board 300 also defines a mounting portion 306 for mounting orientation plate 310 and is located along the longitudinal axis 304. In one aspect, mounting portion 306 defines a generally square recess in the upper surface of board 300 and centered on the center axis 302, the recess having a width of 1.25 inches and a depth of 0.2 inches. Mounting portion 306 also defines a hole 308 of 0.3 inch diameter through the center of the recess along the center axis 302 for securing orientation plate 310. Finally, board 300 defines a plurality of holes 309 (eight shown) for mounting at least one axle assembly 370 on the lower surface of board 300. In one aspect, board 300 defines two sets of four holes 309, positioned on either side of the center axis 302 for mounting two axle assemblies 370 centered on the longitudinal axis 304 and equal distances from the center axis 302.

FIGS. 32-33 illustrate one embodiment of a board assembly 201 of a wheeled shoe accessory. Orientation plate 310 is received by the recess defined by mounting portion 306 and is secured to board 300 by a fastener 318 inserted from the lower side of board 300 through the hole 308 defined by mounting portion 306. Orientation plate 310 (see also FIG. 34) is configured to receive releasable fastener 320 in two or more orientations and defines a center axis 312. In the illustrated embodiment, orientation plate 310 is configured to receive releasable fastener 320 such that their center axes 312 are co-linear and the longitudinal axis 324 defined by releasable fastener 320 is selectively oriented at 0, +45 or −45 degrees with respect to the center axis 304 of board 300. In other embodiments, orientation plate 310 is configured to receive releasable fastener 320 at other desired angles. In this example, orientation plate 310 defines two aligned, parallel half-round protrusions 316 along its upper surface to align releasable fastener 320 in one orientation, and two other sets of protrusions 316 a and 316 b that are received in common, linear slots defined in the lower end of the releasable fastener, for mounting the fastener in two other respective angular orientations about the center axis of the board.

As shown in FIG. 35, releasable fastener 320 is substantially rectangular while having a slightly elliptical profile with a length “L” of 1.125 inches, a width “W” of 0.25 inch, a height “H” of 0.75 inch, and a minor axis “M” of 0.7 inch for the elliptical sides. Releasable fastener 320 defines a hole 326 along its center axis 322 for securing the fastener to orientation plate 310. Releasable fastener 320 also includes a retention feature 328, which in this example is defined by opposing undercuts 328 on either side of the center axis 322 along the longitudinal axis 324. The undercuts 328 are rectangular and span the entire width of the releasable fastener 320 with a depth “d” of 0.2 inch and a height “h” of 0.125 inches. A fastener 330 secures releasable fastener 320 to the orientation plate in a selectable position such that releasable fastener 320 cannot rotate about its center axis 322. When releasable fastener 320 is secured to the orientation plate and the board, retention features 328 are located 0.375 inch from the upper surface of the board. The bottom side of releasable fastener 320 is configured with slots 323 sized and spaced so as to receive the ribs of the orientation plate and prevent subsequent relative rotation of fastener 320.

Referring back to FIGS. 27-28, releasable fastener 320 is received by an attachment mechanism 340 embedded in the sole 220 of an article of footwear 210. As shown in FIGS. 36-38, attachment mechanism 340 includes a body 350 defining a center axis 342 and a longitudinal axis 344. Attachment mechanism 340 is embedded in the sole of the article of footwear such that the longitudinal axis 344 of body 350 is perpendicular to a direction of walking (i.e., perpendicular to the longitudinal, heel-toe axis of the footwear). Body 350 defines along the center axis 342 a cavity 360 configured to receive releasable fastener 320 (FIG. 35). As shown, two buttons 352 are disposed in the body along the longitudinal axis 344 and biased by springs 354 such that the buttons 352 are accessible for actuation on either side of the sole of the shoe. The buttons 352 actuate respective retainer arms 356 disposed in body 350 to operate in opposing directions along the longitudinal axis 344. Each retainer arm 356 is configured to engage a corresponding retention feature of the releasable fastener as the fastener inserted into the cavity 360 (FIG. 38). The springs 354 also bias the retainer arms 356 to engage and retain the inserted releasable fastener. A cover 358 encloses the retainer arms 356 in the body 350.

FIG. 39 illustrates one embodiment of an axle assembly 370. The axle assembly 370 includes a compliant mount 376 resiliently deformable and defining a canted kingpin axis 372. An axle 378 is secured to the compliant mount 376 and rotatable about the canted kingpin axis 372 for inducing yaw with respect to the rolling direction. At least one roller 380 is rotatably mounted on the axle 378 for rolling in the rolling direction.

The wheeled board assembly described above is convertible into a miniature skateboard-like toy, by replacing the releasable fastener and orientation plate with a flat plate 390, as shown in FIGS. 40 and 41. Plate 390 fits flush inside recess 306, and is retained by the same threaded fastener 318 that is shown securing orientation plate 310 in FIG. 33. With plate 390 in place (FIG. 41), the upper surface of plate 390 is coplanar with the upper surface of board 300. For at least smaller children, board 300 so configured is of ample size to enable at least portions of both feet to be placed upon the upper board surface for play.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. 

1. A wheeled shoe accessory comprising: a rigid board having upper and lower surfaces and defining a longitudinal axis configured to be oriented along a rolling direction of the wheeled shoe accessory, the upper surface of the board having a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear; at least one axle assembly secured to the lower surface of the board and comprising an axle and at least one roller rotatably mounted on the axle for rolling in the rolling direction; and at least one releasable fastener configured to secure the board to an underside of the piece of footwear to retain the wheeled shoe accessory to the piece of footwear during use.
 2. The wheeled shoe accessory of claim 1 wherein the releasable fastener comprises a projection extending upwardly from the upper surface of the board, the projection configured to be received by a receptacle defined by a sole of the piece of footwear.
 3. The wheeled shoe accessory of claim 2 wherein the projection is of a shape selected to prevent rotation of the board about an axis normal to the board with the projection received in the piece of footwear.
 4. The wheeled shoe accessory of claim 2 wherein the projection is elongated with its length extending along the longitudinal axis of the board.
 5. The wheeled shoe accessory of claim 1 wherein the releasable fastener is configured to permit the piece of footwear to be selectively positionable on the board in either of two positions, each with the piece of footwear angled with respect to the rolling direction.
 6. The wheeled shoe accessory of claim 1 wherein the board is sized to fit entirely under the piece of footwear.
 7. The wheeled shoe accessory of claim 1 wherein the releasable fastener is securable to the board in either of at least two angular orientations.
 8. The wheeled shoe accessory of claim 1 wherein the board is of a length, measured along the longitudinal axis, of between about 8 and 14 inches, and is of a width, perpendicular to its longitudinal axis, of between about 2½ and 4 inches.
 9. The wheeled shoe accessory of claim 1 wherein the axle assembly further comprises a compliant mount resiliently deformable and secured to the lower surface of the board, the compliant mount defining a canted kingpin axis, the axle secured to the compliant mount and rotatable about the canted kingpin axis for inducing yaw with respect to the rolling direction.
 10. The wheeled shoe accessory of claim 9 further comprising first and second axle assemblies, the compliant mounts secured to the lower surface of the board such that their canted kingpin axes are in opposing directions to one another.
 11. The wheeled shoe accessory of claim 1 in combination with the piece of footwear.
 12. A board assembly for a wheeled shoe accessory, the board assembly comprising: a rigid board having upper and lower surfaces and defining a longitudinal axis configured to be oriented along a rolling direction of the wheeled shoe accessory, the upper surface of the board having a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear, the board defining mounting holes arranged to mount at least one axle assembly on the lower surface of the board; and a releasable fastener defining a center axis and extending upwardly from the upper surface of the board, the fastener defining opposing undercuts on either side of the center axis for receiving an attachment mechanism embedded in an underside of the piece of footwear.
 13. The board assembly of claim 12 wherein the releasable fastener comprises a substantially rectangular mounting boss having a height of about ¾ inch, a length of about 1⅛ inch, and a width of about ¾ inch.
 14. The board assembly of claim 12 wherein the undercuts defined by the releasable fastener are of an elongated shape spanning the width of the releasable fastener and having a height of about ⅛ inch and a depth of about 3/16 inch.
 15. The board assembly of claim 12 further comprising an orientation plate secured to the upper surface of the board and configured to receive the releasable fastener, the orientation plate defining a protrusion along its upper surface to align the received releasable fastener in a particular orientation with respect to the board's longitudinal axis.
 16. An article of footwear comprising: a sole; an upper portion joined to the sole; and an attachment mechanism embedded in the sole for securing a wheeled shoe accessory to the sole, the attachment mechanism comprising: a body defining an elongated receptacle and a longitudinal axis, the receptacle defining a center axis and configured to receive a mounting boss of a wheeled shoe accessory, the body embedded in the sole; and at least one manually operable lock control device configured to engage and retain the received mounting boss within the receptacle.
 17. The article of footwear of claim 16 wherein the receptacle defines a substantially rectangular opening.
 18. The article of footwear of claim 16 wherein the lock control device comprises: a button actuator disposed in the body along the longitudinal axis of the body and accessible from the side of the sole; a retainer arm disposed in the body and joined to the button actuator, the retainer arm configured to engage and retain the received mounting boss in the receptacle with the retainer am in an engagement position; and a spring disposed in the body and biasing the retainer arm toward its engagement position.
 19. The article of footwear of claim 18 wherein the lock control device further comprises two oppositely directed buttons joined to respective retainer arms configured to engage the mounting boss from opposite directions.
 20. A rigid board for a wheeled shoe accessory, the board having upper and lower surfaces and defining a longitudinal axis configured to extend along a rolling direction of the wheeled shoe accessory, the upper surface of the board having a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear, the board defining mounting holes arranged to mount at least one axle assembly on the lower surface of the board, the board also comprising a projection extending from its upper surface and configured to selectively secure a releasable fastener in either of two selectable orientations with respect to the longitudinal axis of the board.
 21. The rigid board of claim 20 wherein the projection comprises two elongated ribs oriented at different angles with respect to the longitudinal axis of the board, and a central post defining a threaded hole therein for receiving a threaded fastener to secure the releasable fastener to the board.
 22. A board for a wheeled shoe accessory, the board having upper and lower surfaces and defining a longitudinal axis configured to extend along a rolling direction of the wheeled shoe accessory, the upper surface of the board having a length along the longitudinal axis sufficient to span a width of a piece of footwear placed sideways across the board, with the board supporting an arch region of the piece of footwear, the board defining mounting holes arranged to mount at least one axle assembly on the lower surface of the board, wherein the board defines a generally square recess in the upper surface along the longitudinal axis for receiving an orientation plate for selectively positioning a releasable fastener secured to the upper surface of the board in a particular orientation with respect to the board's longitudinal axis; the recess having a side length of about 1¼ inches and a depth of about 0.2 inch; the board further defining a hole therethrough at a center of the recess of about ¼ inch in diameter. 